1. Field of the Invention
The invention pertains to a structure defining a cyclonic chamber, which we will simply call the “bowl,” of a device for separation by inertia or cyclonic motion of dust and debris present in an airflow. It is particularly suited for use in a vacuum cleaner. It also pertains to a cyclonic separation device and a vacuum cleaner insofar as they comprise such a bowl.
2. Description of the Prior Art
In prior art, one type of dust and debris collection device for vacuum cleaners consists of a filter in the form of a paper bag, located between an intake tube for an airflow, containing dust and debris sucked from a surface to be cleaned and a suction fan unit. The problem with this solution is the fact that the paper filter bag eventually fills and must be replaced, which is an unpleasant and costly maintenance task for the user. In addition, the filling of the bag negatively affects the performance of the vacuum cleaner since it results in a decrease in its power.
To address these problems, a second type of dust and debris collection device in prior art operates using cyclonic or inertia separation of this dust and debris. In such a device, the airflow is directed into a cyclonic separation chamber, where it follows a vortex path that promotes the separation of debris. In practice, heavier debris is separated from the primary airflow through the centrifuge effect of the vortex flow. Next, the airflow exits the cyclonic chamber through a cylindrical grill positioned against a separation filter located in the center of this chamber, which represents a second, supplementary debris filtration operation, generally collecting dust at this stage. Finally, the dust and debris are contained in a storage area located in the lower portion of the cyclonic chamber. This area must be emptied periodically simply into a trash receptacle through a trapdoor located in the storage chamber.
A cyclonic separation device of this type may be attached to a tank-type vacuum cleaner that also comprises a collection bag, as described in documents FR2817138 and FR2848090.
Another variation of such a cyclonic separation device may be used alone, as is specifically the case for low power vacuum cleaners in which the frame is integrated into a rigid handle manipulated directly by the user, generally called upright vacuum cleaners, as described in document EP1611829.
The performance of cyclonic separation devices is dependent upon numerous parameters, including the speed and direction of the incoming airflow and the capacity of the vortex path to separate debris using the centrifuge method and to prevent a portion of the contaminated air from passing through the separator grill before the debris has been removed using the centrifuge method.
The existing solutions are not entirely satisfactory and the general objective of the invention is to offer an improved solution for cyclonic separation of debris from the airflow entering the vacuum cleaner.